Relapse was defined as any use of alcohol or illicit drugs during the study. Relapse status was determined by examining all available self-report (TLFB, reported reasons for study discontinuation), collateral informant report, medical records, and objective measures (liver enzymes, MCV, breathalyzer, and urine toxicology) of alcohol and other substance use. Participants were classified as relapsers if there was evidence of any drug or alcohol use on any one of those assessments.
